Mission systems typically include hardware components (e.g., computers, network components, sensors, storage and communications components) and numerous embedded software components. Historically, availability prediction for large mission systems has been essentially an educated mix of (a) hardware failure predictions based on well-understood hardware failure rates and (b) software failure predictions based on empirical, historical or “gut feel” data that generally has little or no solid analytical foundation or basis. Accordingly, in availability predictions typical for large-scale mission systems, heavy weighting frequently has been placed upon the more facts-based and better-understood hardware failure predictions while less weighting has been placed on the more speculative software failure predictions. In many cases, mission availability predictions have consisted solely of hardware availability predictions. Hardware, however, is becoming more stable over time, while requirements and expectations for software are becoming more complex.